Commit graph

7 commits

Author SHA1 Message Date
William Baker 3444ec2eb2 fsmonitor: don't fill bitmap with entries to be removed
While doing some testing with fsmonitor enabled I found
that git commands would segfault after staging and
unstaging an untracked file.  Looking at the crash it
appeared that fsmonitor_ewah_callback was attempting to
adjust bits beyond the bounds of the index cache.

Digging into how this could happen it became clear that
the fsmonitor extension must have been written with
more bits than there were entries in the index.  The
root cause ended up being that fill_fsmonitor_bitmap was
populating fsmonitor_dirty with bits for all entries in
the index, even those that had been marked for removal.

To solve this problem fill_fsmonitor_bitmap has been
updated to skip entries with the the CE_REMOVE flag set.
With this change the bits written for the fsmonitor
extension will be consistent with the index entries
written by do_write_index.  Additionally, BUG checks
have been added to detect if the number of bits in
fsmonitor_dirty should ever exceed the number of
entries in the index again.

Another option that was considered was moving the call
to fill_fsmonitor_bitmap closer to where the index is
written (and where the fsmonitor extension itself is
written).  However, that did not work as the
fsmonitor_dirty bitmap must be filled before the index
is split during writing.

Signed-off-by: William Baker <William.Baker@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-12 10:16:11 +09:00
Ben Peart 1fff303fc2 fsmonitor: simplify determining the git worktree under Windows
Simplify and speed up the process of finding the git worktree when
running on Windows by keeping it in perl and avoiding spawning helper
processes.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-13 10:02:20 +09:00
Alex Vandiver 6f1dc21d98 fsmonitor: read from getcwd(), not the PWD environment variable
Though the process has chdir'd to the root of the working tree, the
PWD environment variable is only guaranteed to be updated accordingly
if a shell is involved -- which is not guaranteed to be the case.
That is, if `/usr/bin/perl` is a binary, $ENV{PWD} is unchanged from
whatever spawned `git` -- if `/usr/bin/perl` is a trivial shell
wrapper to the real `perl`, `$ENV{PWD}` will have been updated to the
root of the working copy.

Update to read from the Cwd module using the `getcwd` syscall, not the
PWD environment variable.  The Cygwin case is left unchanged, as it
necessarily _does_ go through a shell.

Signed-off-by: Alex Vandiver <alexmv@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-10 14:04:50 +09:00
Ben Peart 614a718a79 fsmonitor: preserve utf8 filenames in fsmonitor-watchman log
Update the test fsmonitor-watchman integration script to properly
preserve utf8 filenames when outputting the .git/watchman-output.out log
file.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-05 10:12:35 +09:00
Alex Vandiver 2a387b17c5 fsmonitor: read entirety of watchman output
In Perl, setting $/ sets the string that is used as the "record
separator," which sets the boundary that the `<>` construct reads to.
Setting `local $/ = 0666;` evaluates the octal, getting 438, and
stringifies it.  Thus, the later read from `<CHLD_OUT>` stops as soon
as it encounters the string "438" in the watchman output, yielding
invalid JSON; repositories containing filenames with SHA1 hashes are
able to trip this easily.

Set `$/` to undefined, thus slurping all output from watchman.  Also
close STDIN which is provided to watchman, to better guarantee that we
cannot deadlock with watchman while both attempting to read.

Signed-off-by: Alex Vandiver <alexmv@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-04 18:58:53 +09:00
Ben Peart dcdb71f159 fsmonitor: MINGW support for watchman integration
Instead of just taking $ENV{'PWD'}, use the same logic that converts
PWD to $git_work_tree on MSYS_NT in the watchman integration hook
script also on MINGW.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-04 11:10:24 +09:00
Ben Peart 5c8cdcfd80 fsmonitor: add test cases for fsmonitor extension
Test the ability to add/remove the fsmonitor index extension via
update-index.

Test that dirty files returned from the integration script are properly
represented in the index extension and verify that ls-files correctly
reports their state.

Test that ensure status results are correct when using the new fsmonitor
extension.  Test untracked, modified, and new files by ensuring the
results are identical to when not using the extension.

Test that if the fsmonitor extension doesn't tell git about a change, it
doesn't discover it on its own.  This ensures git is honoring the
extension and that we get the performance benefits desired.

Three test integration scripts are provided:

fsmonitor-all - marks all files as dirty
fsmonitor-none - marks no files as dirty
fsmonitor-watchman - integrates with Watchman with debug logging

To run tests in the test suite while utilizing fsmonitor:

First copy t/t7519/fsmonitor-all to a location in your path and then set
GIT_FORCE_PRELOAD_TEST=true and GIT_FSMONITOR_TEST=fsmonitor-all and run
your tests.

Note: currently when using the test script fsmonitor-watchman on
Windows, many tests fail due to a reported but not yet fixed bug in
Watchman where it holds on to handles for directories and files which
prevents the test directory from being cleaned up properly.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-01 17:23:05 +09:00